Method and device for manufacturing bag

ABSTRACT

Bags of plastic film are made by cutting film along transverse lines equally spaced in a longitudinal feeding direction, folding each so-cut film piece along a transverse line, and then sealing the so-folded film piece along a longitudinal line.

United States Patent 1191 Nov. 20, 1973 Kato [5 METHOD AND DEVICE FOR 3,654,015 4 1972 Purcell et al 156 217 MANUFACTURING 33??232 31315 Zli;?i"' 52535??? lnvemorr Takashi Kato, Tokyo, Japan 2:767:756 10 1956 Niles 156 217 x t 2,971,874 2/1961 Canno 156/269 X [73] Assgnees' Musashm" Mew! 3,379,594 4/1968 Bruder 156/292 Cmnlmny P' f f 2,777,574 1 1957 Brody 206 62 f f z g p y Llmlted 2,990,875 7 1961 Samuels et al 156 251 x 0 yo, apan [22] Filed: July 30, 1970 FOREIGN PATENTS OR APPLICATIONS [21] pp No: 59,561 647,026 12/1950 Great Britain 156/510 [30] Foreign Application Priority Data i ary ExaminerGe0rge F. Lesm es July 30, 1969 Japan 44/59695 Ass'smm Epstem i Att0rneyMart1n Smolownz [52] US. Cl. 156/443, 93/8 R, 93/35 R, 156/256, 156/510, 156/204, 156/217, 156/251 [51] Int. Cl ..B3lb U26, B3 57 ABSTRACT [58] Field of Search 156/204, 213, 251, 443,

3 515, 269, 227, 270, Bags of plastic film are made by cutting film along 159/256 220 R, 35 73/2 transverse lines equally spaced in a longitudinal feeding direction, folding each so-cut film piece along a transverse line, and then sealing the so-folded film [56] References C'ted piece along a longitudinal line.

UNITED STATES PATENTS 2,698,046 12/1954 Finke 156/510 X 3 Claims, 14 Drawing Figures Patented Nov. 20, 1973 3,773,596

8 Sheets-Sheet 1 Patented Nov. 20, 1973 3,773,596

8 Sheets-Sheet Z INVENTOR 7k Kflsm A To BY MM W ATTORNEY Patented Nov. 20, 1973 8 Sheets-Sheet 5 INVENTOR BY Muir 5 M ATTSfiNEY Patented Nov. 20, 1973 8 Sheets-Sheet 4.

INVENTOR BY M g ATTO EY Patented Nov. 20, 1973 3,773,596

- NNNNNN OR Patented Nov. 20, 1973 3,773,596-

8 Sheets-Sheet 6 IN VENTOR TA/ 17$ HI K9 Patented Nov. 20, 1973 3,773,596

8 Sheets-Sheet 7 INVENTOR Patented Nov. 20, 1973 3,773,596

8 Sheets-Sheet 8 INVENTOR THKfiSH/ K9 0 BY Nut ATT EY METHOD AND DEVICE FOR MANUFACTURING BAG The present invention relates to the manufacturing of bags or sacks of plastic films or of film such as paper, cellophane, and aluminum foil, laminated with plastic; and more particularly from plastic film stock in the form of a long belt.

Heretofore, film was folded along a longitudinal line which extends in the film feeding direction, sealed along a transverse line which extends vertically to the film feeding direction, and cut into pieces to form sacks.

Such prior devices had drawbacks, as follows:

1. Depth of the sack was limited to one half of width of the film, because the film was folded along a central longitudinal line. Speed of production was low, because the sealing steps had to be accomplished one by one, and intermittently.

2. It was necessary to split the film when wide width film was employed as stock, which required a complicated process, before feeding the film to the sack manufacturing device.

3. Creasing of the film occurred frequently in the film folding step, making an article of inferior quality as long as the crease lasted.

4. Generally, film is strong in longitudinal direction but weak in transverse direction as the molecules of film are oriented in longitudinal direction, so that the bags so produced were weak in the bags longitudinal direction which receives the gravity of article inserted, since the transverse direction of film, that is weak, became the longitudinal direction of the bag.

The main object of the present invention is that of substantially eliminating the above-mentioned drawbacks encountered in the prior art, by providing a method and device for folding film along lines transverse to the film feeding direction, and making the sofolded portion of the film at the bottom of bag.

Another object of the invention is that of folding wide width film along a transverse line, and producing a plurality of bags in one step continuously, and with high efficiency.

A further object of the invention is that of folding a film piece after it had been cut and preventing the possibility of the generation of crease. It does not affect another film piece if a crease occur in one film piece, and thus minimizes the production of articles of inferior quality.

The fourth important object of the invention is to produce bag, the longitudinal direction of the bag which receives the gravity of inserted article, is the longitudinaldirection of film.

An additional object of the invention is to produce bags which have no bottom seal, since the bottom of the sack is formed by a folded portion of the film.

A still further object of the invention is to provide a bag manufacturing device to fold each film piece precisely at a predetermined position, the folding step being performed immediately after the cutting step.

Further characteristics and advantages of the invention will better appear from the following detailed description of a few preferred, not exclusive embodiments of the invention illustrated by the accompanying drawings, in which:

FIG. I is a side elevational view of an embodiment of the invention.

FIG. 2(a) is a side view of the outer face of such embodiment of the invention. FIG. 2(b) is a side view of the driving mechanism of the device.

FIG. 3 is a fragmentary partly sectional perspective view of the cutting and folding mechanism of the device.

FIG. 4 is an enlarged cross-sectional of the cutting mechanism.

FIG. 5 is'a fragmentary view of the folding position adjusting means.

FIG. 6 is a fragmentary side view of the folding mechanism.

FIG. 7 is a perspective view of the sealing and cutting means.

FIGS. 8(a) (b) (c) (d) and (e) are perspective views of each film piece according to the process from film to bag.

FIG. 8(]) is a perspective view of a modified bag.

The principal features of the present invention include animproved apparatus for manufacturing a plastic film bag including: a supply roller for advancing film drawn from a roll, as such film is being held in tension by a tension roller means; first roller guide means for guiding and conveying said film in a downstream direction; second guide means adapted to orient said film with respect to a cutting means adapted to cut a piece of film along a transverse line with respect to film conveying means disposed further downstream in the film travel direction; film folding means adapted to fold the middle portion of a film piece along a transverse line in opposition to said film conveying means; a film folding blade adapted to foldably position said film piece into said film folding means; feed means driven in cooperation with said film folding means adapted to advance said folded film piece to sealing means for sealing said folded film piece in a longitudinal direction.

Also within the scope of the present invention is a method of manufacturing a plastic film bag or the like, including the steps of: feeding plastic film from a roller on a supply roller to guide said film through a series of roller for imprintation thereon and drying of such imprintation: passing said imprinted film through an adjusting roller adapted to orient said film for cutting by a blade of a rotating cutter roller; severing a section of film from said web along transverse lines equally spaced from each other in the longitudinal direction;

advancing the severed section of said film toward a pair of folding rollers whereby the middle portion of the film section is folded along a predetermined line and urged into said folding rollers; advancing the folded piece of film to a series sealing rollers for sealing along a longitudinal line at equally spaced intervals in a transverse direction; advancing said sealed film for cutting along the center of said aforementioned longitudinal line to form a finished bag; and delivering said cut and sealed bag to a receiving receptable.

A further feature of the present invention is directed to a film adjusting means for fixing the relative folding line of said film with respect to the several edge portions of said film; including rotating means for successively rotating a screw means through a shaft having associated therewith a series of interacting gear means for relative movement of said film with respect to said folding rollers.

With reference to FIG. 1, plastic film l to be worked upon is unwound from a roller 2 and is guided in its travel by guide rollers 3, 4 and 5, as well as a tension roller 6 positioned in front of roller 2. Positioned above the tension roller 6, is an expander roller 7, and a printing drum 8 which in turn contacts the printing roller 9, contacting transfer roller 10 which contacts with ink roller 11 which dips into ink pan l2.

Forwardly of and above the printing drum 8, are guide rollers 15 and 16 of film 1, and the film 1 is fed between a drive roller 18 and nip roller 19 through feed adjusting roller 17. Hot air nozzles 20 and 21 for drying ink are disposed above rollers 15 and 16. The drive roller 18 is connected to a driving shaft A through a chain a1, sprocket wheel a2 and a3 and chain a4, (FIG. 2b).

Forwardly of and beneath the drive roller 18, is a guide plate 25, and beneath the guide plate, a rotating cutter roller 26, and a blade 27 are provided.

As shown in FIG. 4, the cutter roller 26 has a blade 30 extending parallel to a shaft 29 of cutter roller 26, which cutter roller cooperates with the blade 27. Shaft 29 is connected to sprocket wheel a3 through chain bl, sprocket wheel b3, power transmission conventer (not shown), and sprocket wheel b4 as shown in FIG. 2b.

Forward and beneath the blade 27, a pair of rollers 31 and 32 are provided along the film feeding direction as well as a plurality of film feeding belts which wind around said rollers 31 and 32. A tension rollers 33 is provided beneath the roller 31 and 32, there is also provided a guide plate 24 along the path of the film 1.

As shown in FIG. 5, beside the roller 32, a pair of the rails 35 and 35 are fixed paralled to the passage of the film 1, and a slider 36 is inserted between rails 35 and 35 and moves slidably there between. Screw bolt 39, which is rotatably supported in bearing 38 is adapted to positively fit threaded hole 37 provided at lower part of said slide. The screw bolt 39 is connected to a handle 44 through shaft 40, bevel gears 41 and 42, and shaft 43. The slider supports the roller 32 and a pair of folding rollers 45 and 46, which contact each other and are opposed to the roller 32. Roller 32 and folding roller 45 are connected to a sprocket wheel a2 through chain c1, sprocket wheel c2, chain c3, sprocket wheel c4 c5, chain c6, sprocket wheel c7, and said chain a1. Lower part of lever 47 is pivoted via shaft 54 on slider 36, such shaft is fixed to the opposite side of the folding plate 48 to fold film 1 into said folding roller 45 and 46. Cam roller 49 pivoted on the middle portion of said lever 47, engages cam 51, which is fixed on shaft 50 which in turn is connected to sprocket wheel b2 through chain d1, sprocket wheels d2, d3, chain d4, sprocket wheels d5, d6 and chain d7.

According to FIG. 7, belts 52 wind around the roller 45 and roller 53 provided in front of said roller 45 for feeding the folded film piece. Belts 59 wind around rolls 53 and 55, and tension roller 57. Above and beneath the film passage provided by said belts 59 and 59, shafts 61 and 62 are provided with sealing rollers 63 and 63 for sealing the film l longitudinally.

Shafts 65 and 66 have cutter rollers 67 and disposed thereon a receiving cutter roller 68, respectively, to cut the intermediate portion of sealed portion of the film 1.

Receptacles 69 and 69 are provided in front of roller 55 to receive each film sack.

The operation of the inventive device is, as follow:

As shown in FIG. 1, film 1 is continuously unwound from roller 2 and delivered on printing drum 8 through guide rollers 3 4 and 5, tension roller 6, and expander roller 7 and printed with a predetermined mark or character.

The film 1 passes guide rollers 15 and 16 while ink printed on the film is dried by heated air from nozzles 20 and 21.

Next the film 1 passes adjusting roller 17, so as to properly orient the printed position to the cutter position, between drive roller 18 and nip roller 19, then film 10 passes by blade 27 and is cut by the blade 30 of rotating cutter roller 26 along the transverse lines 1a, lb, (see FIG. 8) equally spaced from each other in the longitudinal direction. Thus, film piece is fed on the belt 34 between rollers 31 and 32.

When the front end of film piece has passed the roller 32 and middle portion of the film piece is opposite to the midway of folding rollers 45 and 46, cam 51, presses cam roller 49 in the right direction (see FIG. 5), lever 47 rotates clockwise and blade 48 folds the middle portion of film piece along the line yI,y2, in a manner shown in FIG. 8b into folding rollers 45 and 46, as shown in FIG. 6.

The middle portion of the film piece is drawn into folding rollers 45 and 46, and the film piece is folded completely, as shown in FIG. 8c. The folded film piece passes through folding rollers 45 and 46 and continues in its travel via belt 52 and roller 53. When the film piece passes between sealing rollers 63 and 64, the film is sealed along the longitudinal line xI, x2. .equally spaced in transverse direction as shown in FIG. 8d. Then the film passes between cutter roller 67 and receiving cutter roller 68, the film being cut at center of said line X1, X2. .longitudinally. Thus the film is cut and sealed in bag form, and delivered into receptacle 69.

In above described apparatus, when shaft 43 is rotated by handle 44, screw bolt 39 rotates through bevel gears 41 and 42 and shaft 40, slider 36 moves along the passage of film with folding rollers 45 and 46 and plate 48, and the relative position of the film piece and plate 48 varies. Thus, it is possible to adjust the position of the folding line in the film piece so as to fold the film piece to coincide edge In with edge 1b, as shown in FIG. 8c, or to offset the respective edges 1a, 1b by a predetermined length, as shown in FIG. 8f to form a lip portion (lapel) in the bag.

As is apparent from the foregoing specification, the method and apparatus of the present invention are susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. For this reason it is fully understood that all of the foregoing is intended to be merely illustrative and is not to be construed or interpreted as being restrictive or otherwise limiting of the present invention, excepting as set forth and defined in the hereto appended claims.

I claim:

1. An apparatus for manufacturing a plastic film bag including: a supply roller for advancing film drawn from a roll, as such film is being held in tension by a tension roller means; first roller guide means for guid ing and conveying said film in a downstream direction; second roller guide means adapted to orient said film with respect to a cutting means to thereby cut such film along a transverse line with respect to film conveying means disposed further downstream in a film travel direction; film folding means adapted to fold the middle portion of a film piece along a transverse line in opposition to said film conveying means; a rotational adjusting means for fixing the folding line of said film with respect to the several edge portions of said film by relative movement of said film with respect to said folding rollers; a film folding blade adapted to foldably position said film piece into said film folding means; feed means driven in cooperation with said film folding means enabling advance of said folded film piece to sealing means for sealing said folded film piece in a longitudiported on said slider. 

1. An apparatus for manufacturing a plastic film bag including: a supply roller for advancing film drawn from a roll, as such film is being held in tension by a tension roller means; first roller guide means for guiding and conveying said film in a downstream direction; second roller guide means adapted to orient said film with respect to a cutting means to thereby cut such film along a transverse line with respect to film conveying means disposed further downstream in a film travel direction; film folding means adapted to fold the middle portion of a film piece along a transverse line in opposition to said film conveying means; a rotational adjusting means for fixing the folding line of said film with respect to the several edge portions of said film by relative movement of said film with respect to said folding rollers; a film folding blade adapted to foldably position said film piece into said film folding means; feed means driven in cooperation with said film folding means enabling advance of said folded film piece to sealing means for sealing said folded film piece in a longitudinal direction.
 2. A device as claimed in claim 1, in which the means acting to fold the middle portion of film piece on such transverse line, does so while the film piece slides in the film feeding direction.
 3. A device as claimed in claim 2 comprising a film slider, a lever pivoted on said slider, a plate fixed to the end of such lever, and a folding roller rotatably supported on said slider. 